When is an instance that the characters use deception and noting within Much Ado About Nothing by William Shakespeare?

FRIAR FRANCIS Hear me a little; For I have only been silent so long And given way unto this course of fortune. ... By noting of the lady I have mark'd A thousand blushing apparitions To start into her face, a thousand innocent shames In angel whiteness beat away those blushes; And in her eye there hath appear'd a fire, To burn the errors that...

FRIAR FRANCIS Hear me a little; For I have only been silent so long And given way unto this course of fortune. ... By noting of the lady I have mark'd A thousand blushing apparitions To start into her face, a thousand innocent shames In angel whiteness beat away those blushes; And in her eye there hath appear'd a fire, To burn the errors that these princes hold Against her maiden truth. (IV.i)

One of the most famous scenes in Much Ado About Nothing involves "noting," which is the Renaissance pronunciation of "nothing" (rendering the title Much Ado About Noting). It is Hero's wedding day and Claudio accuses her of the deception of infidelity. As the accusation and responses rage, Hero faints. Benedick and Beatrice remain, along with Leonato, Hero's father, and Friar Francis. As worry, fear and outrage commingle, the Friar interrupts and, belatedly, "For I have been silent too long," comes to Hero's defense. He asserts that he noted her complexion as Claudio and the Prince spoke; that he noted the "fire" of wrath in her eyes that would "burn" the false accusations from their lips. Because of what he has noted, Friar Francis believes and defends her and devises the plan that restores Hero's honor and marriage hopes.

DON JOHN ... whatsoever comes athwart his affection ranges evenly with mine. How canst thou cross this marriage?BORACHIO Not honestly, my lord; but so covertly that no dishonesty shall appear in me.DON JOHN Show me briefly how. (II.ii)

The central instance of deception, around which the play revolves, occurs is II.ii when Borachio unfolds for the angered Don Jon the plan to dishonor and discredit Hero, which will stop the marriage between Claudio and Hero. Don Jon has asked Borachio how he might be able to thwart the marriage to prevent it from taking place. In response to which, Borachio reveals his villainous plan for Margaret to impersonate Hero and entertain Borachio in Hero's bed chamber in front of the uncurtained window. It is thus that Borachio intends on making the watching Count Claudio and Don Pedro believe that Hero is faithless and undeserving of Claudio's love and high position. This is the deception that drives the plot to Hero's supposed death, then to the play's resolution.